A Graphics Processing Unit (GPU) is a microprocessor dedicated to image data operations on a computer system, which is used to convert the display information required by the computer system for driving, to provide row scan signals to a display and control the display for displaying normally.
Existing interfaces mostly used between the GPU and an IC chip of the display are TTL (Transistor-Transistor Logic) interface, LVDS (Low Voltage Differential signaling) interface, etc. When gray scale data is transmitted, gray scale values of subpixels in each of pixel units on the display are transmitted to the IC chip on one bus respectively. By taking a picture of 1280*800 pixels as an example, each of rows has 1280 pixel units each consisting of three subpixels, R, G and B, and therefore the GPU has to transmit 1280*3 values to the IC chip sequentially in order to transmit the gray scale values of each subpixel respectively as an image of the row is displayed.
FIG. 1 shows an existing transmission format for 8-bit gray scale data wherein 4 pairs of physical lines are required in total to represent 4 rows of gray scale data. For example, when the gray scale value of the subpixel R to be transmitted is 255 (which is converted to 11111111 as a binary value), R0-R7 are all at a high level at this time, while G0-G7 and B0-B7 are all at a low level, so that the IC chip can determine the gray scale value of the current R subpixel as 255 when it receives the data in such format, and in turn outputs the same to a corresponding pixel point on the display.
It can be seen that the 8-bit gray scale data can only have 256 levels, namely 256 gray scale values at most, that is, 0-255, but many gray scale data are transmitted repeatedly when the gray scale data is transmitted. By taking the transmission format of the 8-bit gray scale data illustrated in FIG. 1 as an example, a large number of repeated transmissions would constraint a transmission rate between the GPU and the display, resulting in a waste of resources and in turn increase power consumptions of the GPU and the display.